Instrument for laying out the cutting edges of cutter-knives.



R. D. EMERY.

INSTRUMENT FOR LA-YING OUT THE CUTTING EDGES 0F CUTTER KNIVES APPLICATION HLED on. 3. 191?.

1,802,645. Patented May 6, 1919.

2 SHEETS-SHEET I.

, W lzi oza gvr R. u, EMERY INSTRUMENT FOR LAYING OUT THE CUTTING EDGES 0F CUTTER KNIVES.

APPLICATION FILED OCT. 3 I917.

Patented May 6, 1919.

2 SHEETS-SHEET 2.

M II/ .Dzvenfor:

ms Nwems PETERS m, PNOTO-LITHOH WASHINGYDN, a c.

UNITED STATES PATEN OFFIC 1? RAYMOND D. EMERY, OF WINCHENDON, MASSACHUSETTS, ASSIGNOR T0 WILLIAM M. WHITNEY, OFWIN'CI'IENDON, MASSACHUSETTS..

INSTRUMENT FOR LAYING OUT THE CUTTING EDGES 0F CUTTER-KNIVES.

Specification of Letters Patent. Patented llLay 6, 1919.

Application filed. October 3, 1917. Serial No. 194,599.

To all whom it may concern Be it known that I, RAYMOND D. EMERY, a

citizen of the United States, residing at VVinchendon, county of Worcester, and State of Massachusetts, have invented anlmprovement in Instruments for Laying Out the Cutting Edges of Cutter-Knives, of wh ch the following description, in connection wlth the accompanying drawings, is a specification, like characters on the drawings representing like parts.

The invention hereinafter described relates to instruments for laying out the cutting edges of knives of cutters for giving the desired shape to moldings and other articles.

Such cutters usually comprise a body hav ing a plurality of knives secured thereon adapted to act progressively on the molding stock to produce the desired contour thereon when the stock is fed past the cutter. In order that these knives may efficiently cut the stock, it is customary to so mount them on the body of the cutter that the planes thereof will be oblique to the plane of the stock when acting thereon. The arrangement of the knives with respect to the body of the cutter is such that the'planes of the knives are tangent to a circle which is concentric to the axle of rotation of the body of the cutter.

If the plane of each knife extended radially of the cutter, said plane would be perpendicular to the plane of the stock when the knife is attaining its greatest depth of cut therein, and the contour of the cutting edge of the knife at such time would truly conform to the contour desired to produce on the molding. But when the knife is tilted from a plane perpendicular to the stock, to a plane oblique to the stock, certain points on the knife edge will move toward the stock away from the axis of rotation of the cutter. Consequently, the contour of the oblique knife must differ from the contour to be produced on the molding sufiiciently to compensate for the change in position of said points.

I am aware that heretofore instruments have been-devised for laying out the cutting edges of knives to compensate for this obliquity, but they are objectionable for various reasons. Among others, they require an objectionablylong time to operate; they require the exercise of great skill and care in the use thereof; and even then inaccuracies are liable to occur.

By my invention, an instrument is provided which enables the cutting edges of knives for the purposes described to be quickly and easily laid out without error.

The invention may be best understood by the following description of one good form of instrument shown in the accompanying drawings, wherein Figure 1 is a side elevation of a rotary "cutter showing the correct contour-of the cutting edge of the knife, and showing the contour of a cross sectionof a piece of molding produced by said knife, the relation of the knife to the molding when making its deepest out being shown in dotted lines;

Fig. 2 is an end elevation of the, cutter shown in Fig 1, and a side elevation of the piece of molding shown therein, the position 'of the knife when making its deepest out being shown in dotted lines;

Fig. 3 is a face view of a knife showing the contour of the cutting edge thereof and a cross section through a piece of molding showing the contour thereof produced by said knife, the knife being shown perpendicular to the plane of the molding toillustrate the difference between the contour of the knife and the contour of the molding;

Fig. 4 is an end elevation of the knife and a side elevation of the piece of molding shown in Fig. 3; also showing the change in position of a point on the edge contour when the knife is in a position perpendicular to the molding as lndicated in dotted lines;

Fig. 5 is a diagram to be referredto;

Fig. 6 is a perspective view. of the instru- Fig. 9 on an enlarged scale is a transverse section taken on line 9-9 of Fig. 7.

Referring to the drawings, a rotary cutter of usual construction, is shown in Figs. .l and 2 mounted on a shaft 1 and comprises a body 3 conveniently square in section, ha ing knives 5 secured on two sides thereof by screw bolts 7. Each knife has a beveled edge 9 which has a contour .for producing the desired contour on a piece of molding 1.1. It will be noted that the contour of the knife is somewhat different from the con tour of the molding, but when the cutter is rotated to bring the knife in a position oblique to the plane of the molding, as indicated at 13, the contour of the knife exactly conforms to the contour of the molding.

The difference between the contour of the cutting edge of the knife and the contour to be produced thereby on the molding, may be readily understood by reference to Fig. 3, inwhich the knife is shown rocked to a position perpendicular to the planeof the molding. When the knife is oblique to the plane of the molding as shown in Fig. 4, the points onthe contour thereof will fit the contour of the molding, but when rocked to its position shown in dotted lines in said figu're, where it is perpendicular to the plane of the molding, certain points thereof will be elevated above the contour of the molding. For example, when the knife is in its oblique position, the point a on the knife will engage the point a on the molding, but when the cutter is rocked to its perpendicular position, this point will have moved to the position indicated by I), and will have moved away from the molding a distance represented by a'-b in Fig. 3.

To facilitate an understanding of the invention, reference may be had to the diagram shown in Fig. 5 wherein 15 designates a pattern of paper or other suitable material having a contour 16 of the desired de sign thereon, and supported a distance as from a knife blank 17, corresponding to the distance between the axis of rotation 19 of the cutter and the plane of the knife. This distance will vary aecording to the size of cutter required. The pattern is also placed a distance y from said axis, corresponding to the radial distance of the cutting edge ofthe' knife from said axis. The pattern is ina plane containing the axis of rotation of the cutter, and theknife blank is in a plane tangent to a circle 20 concentric with the axis of the cutter. Tracer means 21 is adjusted progressively along the contour of the pattern in the direction of the axis 19, and swung down about said axis until it engages the knife blank, and traces thereon a pattern having points at distances from said axis determined by the distances of progressive points on the pattern from said axis.

The instrument selected herein to illustrate the invention comprises a base 23 (Fig. 6) having a suitable support rising therefrom, in the present instance of the inven tion, in the form of posts 25 mounted adjacentthe rear edge of the base. These posts serve to support a member having an axis corresponding to the axis of rotation of the cutter, said member being conveniently in the form of a bar 27 mounted in brackets 29 having split ears 31 receiving thumb screws 33, whereby the brackets may be secured to said posts at different elevations from the base.

Suitable means is provided for supporting the patterns 15, referred to. In the present instance of the invention, a table 35 is provided for this purpose mounted on and secured to an arm 37 projecting from one of the brackets29, the construction being such, that the upper surface of the table is in a plane containing the axis of the bar 27, which corresponds to the axis 19 in the diagram, referred to. The pattern may be secured on the upper surface of the table by thumb tacks 39 or other suitable means. The contour of the pattern should be at a distance from the axis of the bar corretion, a table 41 is mounted 011 the base 23 and secured thereto by an angle bar adapted to be clamped to the table by screws 415 which may be threaded into selected holes of a series of tapped holes 4-7 in the table 41.

The knife blank support, and the pattern support and bar may be relatively adjusted in order that the distance between the upper surface of the knife blank and the upper surface of the pattern support and bar may correspond to the distance required between the knife and the axis of rotation of the cutter. In the present exemplification of the invention, this adjustment is obtained by elevating or lowering the pattern support and the horizontal bar, along the posts 25, but obviously instead of adjusting said parts, the knife blank table might be adjusted to accomplish this purpose.

The tracer means for laying out on the knife blank a contour suitable to produce the contour of the pattern, in the present instance of the invention, comprises an arm 49 which should be adjustable to vary the effective radial length thereof or distance between the contour of the pattern edge and the axis of said bar; and should be adapted to slide in the direction of the axis of said bar; and should be able to rock about said axis. To perform these functions, the arm, in the present instance of the invention, is mounted in a boss 51 on a stem 53 rising from a sleeve 55 adapted to slide along and rock on said bar.

The arm may slide in the direction of the length thereof in said boss 51 and be frictionallyheld in different positions of extension by a spring-pressed plug 57 (Fig. 9,) mounted in the stem 53 and adapted to engage a flat face 59 of said arm. The engagement of the plug with said face will also tend to prevent rotation of said arm in said boss.

A tracer or pin 61 may be mounted in a hole in the front end of said arm and be secured in different positions of adjustment by a screw '63 adapted to press split portions of said arm against said pin. A knob or handle 65 on said pin facilitates manipulation thereof.

The construction described is such that the tracer may be moved progressively along the pattern and progressively along the knife blank to mark or lay out the desired contour thereon. In the present instance of the invention, the tracer is adjusted from point to point along the pattern equal increments and is shifted from each point to lay out a corresponding point 011 the knife blank.

Suitable means may be provided for determining equal adjustments of the tracer along the pattern and knife blank. To accomplish this, in the present instance of the invention, a pair of scales 67 and 69 (Figs. 6 and 7 are provided, one opposite the pattern support and the other opposite. the knife blank support. These scales are similar and each comprises a series of graduations conveniently on the horizontal bar 27 and marked with numbers to facilitate the reading thereof. A recess 71 in said sleeve 55 discloses the. scales, and index lines 7 3 on the edges of said recess are adapted to be read in connection with the graduations of the scales.

In use, the pattern 15 is mounted on the table 35 with its contour a distance from the axis of the horizontal bar 27 corresponding to the required distance between the cutting edge of the knife to be produced and the axis of rotation of the cutter. The knife blank 17 is mounted on and secured to the table 41 in appropriate position. Then the thumb screws 33 are loosened to allow adjustment of the horizontal bar and pattern table along the post 25 to set the upper surface of said table a distance above the knife blank corresponding to the distance required between the plane of the knife and the axis of rotation of the cutter, and the thumb screws are tightened to secure the table in this position. Then the knob 65 of the tracer 61 is grasped to set the same at one end of the pattern contour, such, for ex ample, the right end thereof (Fig. 6).

After the index line 73 is read in connection with the scale 6?, the tracer arm is moved along said bar to the left of Fig. 6 to a corresponding reading on the scale 69. It is then rocked downward to its position shown in dotted lines in Fig. 6, thereby bringing the tracer into engagement with the knife blank to mark a point thereon. The tracer is then returned to its position above the pattern support and applied to the contour of the pattern at a point spaced from the first point a selected increment.

The index 73 is read again in connection wlth the scale 67 and the tracer is ad usted along the horizontal bar to the left of Fig.

G to a corresponding position on the scale 69. The tracer is then rocked downward to mark a second point on the knife blank; and so on points may be taken progressively from the pattern and laid out on the knife blank until the complete contour is obtained.

The marginal portion of the knife blank between the contour thus laid out thereon, and the end of the blank adjacent thereto may be removed in a suitable grinding machine. Thus, a knife will be produced having a cutting edge with a contour compen eating for the change therein from the contour of the pattern, made necessary by the obliquity of the plane of the knife with the plane of themolding when cutting thereon.

By the instrument described, it will be apparent that any pattern may be selected and the correct contour of a knife edge for reproducing the pattern on a knife blank maybe quickly and easily obtained without opportunity for error in laying out the same.

While the instrument has been described more particularly for laying out the contour of a knife edge of a cutter for shaping moldings, it will be understood that. its field of usefulness is not restricted thereto, but that it may be employed for laying out the contours of other articles.

It will be understood that the instrument disclosed herein is selected as one embodiment of the invention, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is:

1. An instrument for laying out the cutting edges of knives of molding cutters and the like, comprising, in combination, a guide member, means to support a pattern a distance from the axis of said member determining the radial distance of the cutting edge of the cutter from the axis of the cut ter head, means to support a knife blank a distance from the axis of said member determining the distance of the plane of the knife from the axis of the cutter head, and tracer means arranged to rock transversely about and slide axially of said member to lay out on said knife blank a'contour determined by adjustments of said tracer means to progressive points on said pattern.

2. An instrument for laying out the cutting edges of knives of molding cutters and the like, comprising, in combinatioma guide member having an axis correspondingto the axis of rotation of a cutter head, a pattern. support having its upper surface in a plane containing said guide member axis, means to support a knife blank in a plane offset from said axis and pattern support, and tracer means constructed and arranged to swing about and move parallel to the axis of said member to lay out a contour on said knife blank determined by the distance of said pattern from said axis.

3; An instrument for laying out the cutting edges of knives for molding cutters and the like, comprising, in combination, a guide member having an axis corresponding to the axis of rotation of a cutter head, a support for a pattern having its upper surface in a plane containing said guide member axis, means to support a knife blank in a plane tangent to a circle concentric with said axis, and means mounted on said member adjustable to lay out a contour on said knife blank determined by the distance of said pattern from the axis of said member.

4. An instrument for laying out the cutting edges of knives of molding cutters and the like, comprising, in combination, a member having an axis corresponding to the axis of rotation of a cutter head, means to support a pattern, means to support a knife blank in a plane olfset from said pattern, and tracer means movable to positions corresponding to the distances of points on the pattern from said axis, said tracer means being movable on said axis to lay out corresponding points on said knife blank.

5. An instrument for laying out the cutting edges of knives of molding cutters and the like, comprising, in combination, a bar having an axis corresponding to the axis of rotation of a cutter head, means to support a pattern in a plane containing said axis, means to support a knife blank in a. plane tangent to a circle concentric with said axis, tracing means rotatively and slidably movable on said bar to project successive points from said pattern to said knife blank, and scales on said bar opposite said pattern and knife blank supports, for determining the extent of sliding movement of saidtracer means in projecting the successive points.

6. An instrument for laying out the cutting edges of knives of molding cutters and the like, comprising, in combination, a guide member, a support for a pattern, a support for a knife blank, tracer means mounted to slide and rockon said guide member to proj ect points progressively from the pattern to the knife blank, and means to effect equal increments of sliding movement of said tracer means along the pattern and knife blank.

7. An instrument for laying out the cutting edges of molding cutters and the like, comprising, in combination, a support, posts thereon, a guide bar connected to said posts having an axis corresponding to the axis of rotation of the body of a cutter, a table adapted to support a pattern. mounted on said support and having its upper surface in the plane of said axis, a table adapted to support a knife blank in a plane tangent to a circle concentric with said axis, and tracer means mounted to slide along and rock on said bar 0 project points progressively from the pattern to the knife blank.

8. An instrument for laying out the cutting edges of knives of molding cutters and the like, comprising, in combination, a guide member having an axis corresponding to the axis of rotation of a cutter head, means to support a pattern, means to support a knife blank, means permitting relative adjustment of said guide member and knife blank supports to space them distances corresponding to the distances between the knife plane and axis of rotation of different sized cutters, and tracer means mounted to rock on and slide along the axis o'f' said member to lay out on said knife blank an edge contour for reproducing said pattern.

9. An instrument for laying out the cutting edges of molding cutters and the like, comprising, in combination, a guide member having an axis corresponding to the axis of rotation of a cutter head, means to support a pattern, means to support a knife blank in a plane tangent to a circle concentric with said guide member axis, and means guided.

by said member movable along said pattern and blank to lay off a contour on the blank different from the contour of said pattern.

10. An instrument for laying out the cut ting edges of molding cutters and the like, comprising, in combination, a support for a pattern, means to support a. knife blank in a plane offset from the plane of the pattern, guiding means mounted adjacent said supports, and means mounted on said guiding means movable along the pattern and blank to lay off on said blank a contour for reproducing the contour of said pattern.

11. An instrument for laying out the cutting edges of molding cutters and the like, comprising, in combination, a guide member having an axis corresponding to the axis of rotation of a cutter head, means to support a pattern with its contour at distances from said axis varying according to the radius of the cutter, means to support a knife blank in a plane offset from said axis, said guide member and knife blank support being relatively adjustable to space the same according to the size of the cutter head, and means mounted on said guide member adjustable to said pat tern contour and arranged to lay off a cutting edge contour on said knife blank suitable to reproduce said pattern on a piece of work when the knife is oblique to the plane of the work.

In testimony whereof, I have signed my name to this specification.

RAYMOND D. EMERY.

Copies of this patent may be obtained for five cents each,'by addressing the Commissioner of Batents, Washington, D. G. 

